Unit 2

Cell Biology

What two thing do all of these things have in common?

Explain your answer, and be prepare to defend.

WHAT DOES IT MEAN TO BE ALIVE?Part 1

Brainstorm

• List as many characteristics of living things as possible.

– Don’t “think” too much.

– Just write.

– No wrong answers.

– Try to get at least 10.

• 5 MINUTES

Combine and Rank

• With a partner or group of three:

– Combine your brainstorms.

– Put a check mark next to the ten “best” characteristics of life.

– Be prepared to explain/defend your choice.

• 5 MINUTES

Share

• Need three groups to share their lists.

Similarities? Differences?

The 9 Characteristics of Life

• Table 2.1 (page 52)

1. Take in and convert materials and energy from the environment; release wastes.

Short answer: Living things need energy.

2. Have a high degree of chemical organization compared to nonliving objects.

Short answer: Living things are more biochemically complex.

Shorter answer: Living things are made of cells.

3. Have complex structural organization that is responsible for their appearance and activities.

Short answer: Living things have structures that relate to their functions.

4. Contain coded instructions (such as DNA) for maintaining their organization and activities.

Short answer: Living things have “Universal” code.

5. Sense and react to changes in their environment.

Short answer: Living things react to their environment.

6. Grow and develop during some part of their lives.

Short answer: Living things grow.

7. Reproduce others like themselves.

Short answer: Living things reproduce.

8. Communicate with similar organisms.

Short answer: Living things communicate.

9. Move under their own power.

Short answer: Living things move and move stuff.

THE CELL THEORYPart 2

Basic Units of Life

• Started in early 1800s.

• Many scientists contributed ideas.

• Led to two main parts of the CELL THEORY

1. Cells, or products made by cells, are the units of structure and function in organisms.

2. All cells come from preexisting cells.

PROKARYOTES / EUKARYOTESPart 3

Prokaryotes

• First

• Simplest

• Smaller (0.3-5 μm)

• Almost always unicellular

• EVERYWHERE

• Do not have a nucleus

Eukaryotes

• Came after prokaryotes

• More complex

• Larger (10-50 μm)

• Can make up multicellular organisms

• Have a nucleus

Prokaryotic Cell Structure

Structures to know:1. Plasma Membrane2. Cell Wall3. Capsule4. Nucleoid5. Plasmid6. Ribosomes7. Cytoplasm8. Flagellum

Eukaryotic Cell StructureBasic structures:1. Plasma Membrane2. Nucleus3. Cytoskeleton

a. Microtubulesb. Microfilaments

4. Lysosome (a)5. Centrioles (a)6. Cell Wall (p)7. Mitochondrion8. Endoplasmic reticulum (ER)

a. Smoothb. Rough

9. Golgi apparatus10. Cytosol / Cytoplasm11. Chloroplast (p)

a = Animal Onlyp = Plant Only